In January, he said he did not remember being alone with her and never had an affair with her. Last week, he said they had a half-dozen sexual encounters.

In January, he did not recall any specific gifts he gave her. Last week, he named at least three he presented just after Christmas.

In January, he was not sure he talked with her about testifying other than making a joke about it. Last week, he said they discussed how to respond to a subpoena.

President Clinton, famed for a razor-sharp political memory, was uncharacteristically forgetful when he was questioned under oath in the Paula Jones civil case last winter about his relationship with Monica S. Lewinsky. Seven months later, forced to justify those answers during unprecedented testimony in a grand jury criminal investigation by independent counsel Kenneth W. Starr, the president's memory improved.

But in those vague and what Clinton now admits were misleading answers last January lie the contours of his defense against accusations of perjury and obstruction of justice. The bottom line, according to some advisers, is this: Yes, he deceived, obfuscated and evaded. No, he was not forthcoming or fully truthful. But technically, they maintain, he did not lie. And even if he did, it should not matter legally because it was an irrelevant line of questioning in an illegitimate lawsuit eventually thrown out of court.

As details continue to emerge about his account following last week's questioning, presidential advisers acknowledge that they are beginning to shape a Clinton defense strategy that relies heavily on nuance, ambiguity and intent.

"What everybody is doing is looking for defenses," said one lawyer close to the Clinton team.

With the independent counsel writing a report to the House of Representatives on possible impeachable offenses, what is known of the evidence against Clinton so far turns largely on what was said in private conversations, statements that his defenders argue are open to interpretation or, at worst, amount to he-said-she-said disputes. To allies, Clinton's testimony in the Jones case was so fuzzy that it amounted to what one called legal "jello."

Beyond words, the most tangible elements of a possible obstruction case are the retrieval of presidential gifts from Lewinsky to avoid a Jones subpoena last December and the job search instigated on her behalf by Clinton associates at the same time she was considering how to testify in the Jones case. In both instances, the president's advisers maintain that there is no solid evidence of illegal involvement by Clinton.

The President's Deposition

Clinton insisted last week that his answers during the Jan. 17 deposition were "legally accurate," resting on the semantic argument that the definition of "sexual relations" used in the Jones case did not include oral sex.

Even if that were accepted and even if he can somehow explain Lewinsky's testimony that they also fondled each other in ways that would be covered by the definition, the president's admission that they engaged in sexual activities could expose him to possible perjury land mines in other areas of the deposition as well.

For example, regardless of whether their sexual relationship fit the Jones definition, how could he have testified in January that he had "no specific recollection" of ever being alone with Lewinsky in the White House? And having now recalled giving her an Alaskan stone carving, a throw rug and a pin three days after Christmas last year, how could he have testified just three weeks later that "I don't remember a specific gift"?

Moreover, Clinton denied a sexual relationship with Lewinsky at other points in the deposition without citing the Jones definition. Clinton said "no" when asked generally if he had "an extramarital sexual affair with Monica Lewinsky." And if Lewinsky told someone that she had a sexual affair with him beginning in November 1995, he testified, "it would not be the truth."

Clinton also allowed his lawyer to make Lewinsky's Jan. 7 affidavit an exhibit in the Jones case and vouched for its truthfulness under oath, even though it falsely denied any "sexual relationship" (Lewinsky, unlike Clinton, was not provided with a specific definition of sex) and falsely asserted that they had not seen each other outside official functions after she was transferred to the Pentagon in April 1996. The president's attorney, Robert S. Bennett, raised the affidavit to try to curtail questioning about Lewinsky, telling a judge that, in his words, it said "there is absolutely no sex of any kind in any manner, shape or form, with President Clinton."

Bennett added that Clinton was "fully aware" of the details of Lewinsky's affidavit and later read aloud the line: "I have never had a sexual relationship with the president." The president's response: "That is absolutely true."

To constitute perjury, the person making the statement must know it is false and it must be "material" to the case at hand -- that is, capable of influencing the proceeding in which it was made. Statements that are evasive and misleading do not constitute perjury as long as they are technically true; courts have said it is up to lawyers to make their questions precise.

Clinton defenders argue that any misstatements did not constitute perjury because they were not material to the Jones lawsuit. A federal judge, concluding that Lewinsky was not central to the case, later excluded any additional evidence about her from being collected to avoid interfering with Starr's investigation, and eventually dismissed the lawsuit entirely.

"While you may say he wasn't candid about what went on in the Paula Jones deposition, it still comes back to the fact that it wasn't material to the Paula Jones case," said a lawyer close to the Clinton camp. "It may not have been the most candid version, but it wasn't perjury."

Some courts have held that materiality of a statement is judged at the time it is made, not in light of later events. The federal appeals court here generally has applied a low threshold for judging what statements are material. Moreover, the materiality argument would not apply if Starr concludes Clinton committed perjury during his grand jury testimony last week.

Nonetheless, some criminal law experts said they thought the way Clinton dealt with the Jones lawyers -- often answering a different question than was asked and talking about extraneous matters -- could help the president defend himself against perjury accusations.

"Some of his answers are so rambling as to be incoherent," said Fordham University law professor Bruce Green. "It's the job of the person asking the questions in the deposition to pin the person down and get an affirmative statement one way or the other."

The Return of the Gifts

Starr's investigators have focused increasingly on gifts Clinton gave Lewinsky, including a T-shirt, pin and book of poetry, and how they were handled during the Jones lawsuit. In their private deliberations, Clinton advisers appear most concerned about the gifts because they may provide the most concrete evidence of impeding the Jones legal team.

"The obstruction or concealment of materials that have already been subpoenaed and are known to be under subpoena is one of the classic cases of obstruction of justice," said Gerard Lynch, a law professor at Columbia University.

In their testimony, Clinton and Lewinsky agreed that they discussed the gifts and how to respond to a subpoena to turn them over to Jones's lawyers. According to sources familiar with their accounts, the president testified that he told her she had to turn over what she had, while she testified that she heard him say she did not have to turn over anything that was not in her possession.

Shortly after their conversation, Lewinsky reportedly testified, Clinton's personal secretary, Betty Currie, contacted her, saying she understood that the young woman had something for her, and went to Lewinsky's Watergate apartment to collect the gifts.

"Retrieving gifts from somebody is a very unusual thing to do and it's hard to imagine what innocent explanation of that could be offered," said Bradford Berenson, a Washington criminal defense lawyer. "If the president instructed that evidence be hidden so that the Jones lawyers would not get their hands on it, he's committed a very serious felony."

Clinton denied during his testimony that he ordered Currie to retrieve the gifts and said during his televised speech to the nation that he never asked anyone "to hide or destroy evidence." It remained unclear, though, how Currie came to approach Lewinsky to collect the gifts if she was not told to by the president.

The president's defense again comes down to interpretation and intent. If Lewinsky misconstrued him, his defenders argue, then the president cannot be blamed because he did not mean to encourage any obstruction.

"Obviously there's some ambiguity about the gifts," said the lawyer close to the Clinton camp. But "the bottom line is, their stories are consistent and it would take a great deal of exaggeration to make them inconsistent."

Moreover, Clinton allies noted, the fact that he gave her other gifts during a White House meeting on Dec. 28 showed that he was not concerned about them being evidence and confirmed his assertion that he was not aware that previous gifts were returned. And at least some Clinton advisers have floated the argument that it would amount to obstruction only if the gifts had been destroyed.

Much as with perjury, the Clinton defense eventually turns to the contention that even if what he did was wrong, it was not that serious legally. One person informed about the Clinton team's thinking suggested that not turning over evidence in a civil lawsuit typically is punished by disbarment, civil sanctions or a default judgment in the case, not criminal charges.

"At the very worst, this isn't a crime," this person argued. "It's a sanctionable offense."

Independent lawyers, though, were skeptical. Lawrence Barcella, a criminal defense attorney, said "hiding evidence in a court case is almost as bad as destroying it." Other lawyers noted that Clinton would have known it was safe to give Lewinsky new gifts on Dec. 28 because the Dec. 17 subpoena would apply only to gifts given prior to that date.

And even the Clinton Justice Department has concluded that hiding evidence in a civil lawsuit constitutes a criminal offense. Federal prosecutors charged two former Texaco executives with obstruction for withholding and destroying evidence in a race discrimination lawsuit. But there may be solace for Clinton in the outcome: They were acquitted.

The Job Search

The job help provided to Lewinsky by the president's associates opened the way for Starr to expand his Whitewater probe in January, because it appeared to constitute possible obstruction of justice. But the question of whether it was intended to buy her cooperation in the Jones case has come to be viewed by the Clinton team as far less of a problem than it once seemed.

No evidence has emerged publicly so far of a direct quid pro quo; Lewinsky herself testified that she did not see the job help as a big deal and was never told it was conditioned on her testimony, according to a legal source.

Still, the timing and nature of the help may provide Starr circumstantial evidence to build an overall case of perjury and obstruction also relying on the return of the gifts, Clinton's use of Lewinsky's affidavit and her testimony that they developed "cover stories" early in their affair.

Vernon E. Jordan Jr., the Washington attorney and presidential golfing buddy, testified that Currie asked him to help Lewinsky find a New York job on Dec. 8, three days after her name showed up on a witness list provided by Jones's lawyers to the Clinton legal team. In the next month, he also helped her find a lawyer to draft her affidavit, which was submitted on Jan. 16, just after she had received a job offer from Revlon, where Jordan sits on the board of directors.

Clinton said in the Jones deposition that he knew Jordan met with Lewinsky -- at Currie's suggestion, he said -- but thought it was about something other than the Jones case. "I thought he had given her some advice about her move to New York. Seems like that's what Betty said," the president said. But Jordan assumed Currie was calling at the president's behest and told the grand jury that he kept Clinton personally apprised of his efforts on her behalf, according to an associate. He also testified that he asked Clinton whether he had an affair with Lewinsky and was told no, an account verified by the president in his own testimony last week.

All of this amounts to what one Clinton adviser termed "nebulous conduct," and Starr may have a problem proving any intent to influence Lewinsky's testimony. "The issue comes down to: Was there an agreement to change her testimony in exchange for help with a job? The timing doesn't establish that there was any evidence of that," said the lawyer close to the Clinton camp.

The Next Step

The Clinton defense, of course, is a work in progress. With Starr's office laboring to write its report to Congress, the case changes from a legal one to a political one. The House of Representatives will become the grand jury and the White House response may change accordingly.

"Are we talking about a criminal defense or an impeachment defense?" asked Barcella. "One is inherently legal and the other is inherently political."

The White House has begun thinking about how to proceed, but no decisions have been made. For example, will the president's private attorney, David E. Kendall, be in charge of an impeachment defense or will that be left to White House counsel Charles F.C. Ruff or perhaps even a new team altogether?

In addition, fashioning a defense is difficult when all the facts are not yet known. Although Kendall has kept close tabs on much of the testimony provided by other witnesses, even he cannot be certain what will end up in Starr's report. And so, the defense strategy remains a moving target.

As Fordham's Green put it, "It's sort of like you're looking at the tip of the iceberg and trying to describe the whole iceberg."